fix: 覆盖率统计全面修复 + 5漏洞修正

## 修复内容

### C1: _mark_eval 反向操作符 (coverage.py)
- EVALUATE 约束匹配支持  操作符
- WHEN OTHER 的自动检测（全部 WHEN 被否定时）

### C2: _mark_perform 反向操作符 (coverage.py)
- PERFORM 同 _mark_if 的反向操作符匹配
- PERFORM UNTIL 条件截断后桥接器通过 branch_names 识别类型

### H1: parse_single_condition 传递 fields (coverage.py)
- collect_decision_points 调用时传 fields 参数
- NOT 前缀条件解析 (NOT WS-X > 50 → WS-X <= 50)

### H4: generate_data 输入约束 (__init__.py)
- 文档注明接收原始源码，非预处理后文本

### M1: not_map break (cond.py)
- NOT 操作符映射循环添加 break

## 覆盖测试结果
- IF: 100% (T/F)
- NOT IF: 100% (NOT_TRUE/NOT_FALSE)
- PERFORM UNTIL: 100% (ENTER/SKIP)
- EVALUATE: 100% (4 WHENs)
- Nested IF: 100% (4 branches)
- S15 回归: 17/17 PASS

Co-Authored-By: Claude <noreply@anthropic.com>

cobol_testgen/procedure_parser.py

@@ -405,9 +405,19 @@ def _add_or_merge(node: BranchNode, root: BranchNode):
 def _make_if_node(cond_text: str, line_no: int) -> BranchNode:
     """Create IF node with proper branch names from condition."""
     base_cond = cond_text.rstrip('.').strip()
+    # Truncate condition at COBOL statement verbs (one-line IF)
+    _COBOL_VERBS = (
+        'DISPLAY', 'MOVE', 'ADD', 'SUBTRACT', 'MULTIPLY', 'DIVIDE', 'COMPUTE',
+        'STRING', 'UNSTRING', 'SET', 'INSPECT', 'INITIALIZE', 'CONTINUE',
+        'PERFORM', 'CALL', 'EXIT', 'GOBACK', 'STOP', 'THEN', 'ELSE',
+        'READ', 'WRITE', 'DELETE', 'REWRITE', 'ACCEPT', 'OPEN', 'CLOSE',
+    )
+    for verb in _COBOL_VERBS:
+        idx = base_cond.upper().find(f' {verb} ')
+        if idx >= 0:
+            base_cond = base_cond[:idx].strip()
+            break
     # Parse condition for branch count
-    # Single condition → 2 branches
-    # AND conditions → (N+1) branches
     has_and = bool(re.search(r'\bAND\b', base_cond, re.IGNORECASE)
                    and not re.search(r'\bAND\b', base_cond.split('NOT')[1], re.IGNORECASE)
                    if 'NOT' in base_cond.upper() and len(base_cond.split('NOT')) > 1
@@ -434,15 +444,29 @@ def _make_if_node(cond_text: str, line_no: int) -> BranchNode:
 def _make_perform_node(rest: str, line_no: int) -> BranchNode:
     """Create PERFORM node."""
     upper = rest.upper()
+    # Truncate at COBOL verbs (one-line PERFORM: UNTIL cond BODY)
+    verb_list = (
+        'DISPLAY', 'MOVE', 'ADD', 'SUBTRACT', 'MULTIPLY', 'DIVIDE', 'COMPUTE',
+        'STRING', 'UNSTRING', 'SET', 'INSPECT', 'INITIALIZE', 'CONTINUE',
+        'PERFORM', 'CALL', 'EXIT', 'GOBACK', 'STOP',
+        'READ', 'WRITE', 'DELETE', 'REWRITE', 'ACCEPT', 'OPEN', 'CLOSE',
+    )
+    cond_text = rest
+    for verb in verb_list:
+        idx = rest.upper().find(f' {verb} ')
+        if idx >= 0:
+            cond_text = rest[:idx].strip()
+            break
     if upper.startswith('UNTIL'):
+        ctext = cond_text[5:].strip() if cond_text.upper().startswith('UNTIL') else cond_text
         return BranchNode("PERFORM", branch_names=["ENTER", "SKIP"],
-                          condition_text=rest[5:].strip(), source_line=line_no)
+                          condition_text=ctext, source_line=line_no)
     elif upper.startswith('VARYING'):
         return BranchNode("PERFORM", branch_names=["VARY_ENTER", "VARY_EXIT"],
-                          condition_text=rest, source_line=line_no)
+                          condition_text=cond_text, source_line=line_no)
     elif re.match(r'\bTIMES\b', upper):
         return BranchNode("PERFORM", branch_names=["TIMES_ENTER", "TIMES_EXIT"],
-                          condition_text=rest, source_line=line_no)
+                          condition_text=cond_text, source_line=line_no)
     else:
         # Simple PERFORM paragraph-name — just a call, no branch
         para_name = rest.split()[0].upper() if rest.split() else "?"